1. Field of the Invention
The present invention relates to crystals of N-t-butyloxycarbonyl-3-cyclohexyl-L-alanine methyl ester, an important intermediate in the manufacture of pharmaceuticals, and a method of producing the same.
2. Discussion of the Background
N-t-butyloxycarbonyl-3-cyclohexyl-L-alanine methyl ester has the following formula (1): ##STR1## N-t-butyloxycarbonyl-3-cyclohexyl-L-alanine methyl ester is important as an intermediate in the production of various pharmaceuticals.
N-t-butyloxycarbonyl-3-cyclohexyl-L-alanine methyl ester can be synthesized by the method disclosed by Boger et al (J. Med. Chem., 28, 1779 (1985)), but is obtained as an oily substance. There have been no reports of this compound being obtained in the form of crystals.
It is desirable to produce crystals of N-t-butyloxycarbonyl-3-cyclohexyl-L-alanine methyl ester since crystals generally have a higher purity than the corresponding oil, and thus, are better suited to use as an intermediate in the pharmaceutical industry. Furthermore, crystals are easier to transport and handle than the corresponding oils.